Oil spills (or oil discharges) are not uncommon in aqueous bodies such as harbors, waterways, navigation channels as well as the open sea. Such spills typically form a surface layer which may extend over a wide area. In the past, catastrophic effects have been seen from the accidental discharge of oil from tankers, pipes, storage tanks as well as during exploration, drilling and production of oil. In addition to being leaked into aqueous bodies, oil spills are a common occurrence on land surfaces such as cement, concrete and asphalt as well as platforms used during production of oil and gas.
Oil spills are typically difficult to treat and a number of treatment agents have been reported in the literature. For instance, discharged oil has been treated with absorbents such as hay, straw, ground bark, sawdust, peat, wood chips, activated carbon, wool, cotton balls, corn husks, duck feathers, bagasse, treated perlite and polymeric materials such as shredded urethane foam, polyolefin foam, polypropylene, polyester, vinyl polymers, etc.
Synthetic rubbers have also been used as an absorbent. Note, for example, U.S. Pat. No. 3,265,616 which discloses the use of a synthetic rubber latex. See also U.S. Pat. No. 4,182,677 which discloses the use of rubber waste or rubber crumb (including that obtained from used tires) to absorb spilled oil. The crumb rubber may be in the form of a powder whose grains have a size ranging from 0.1 to 1 mm. Other methods have been reported wherein a rubber film is formed by coagulating absorbed oil within a rubber latex. Such absorbents may be placed inside booms or other barriers that surround the spill. Alternatively, such absorbents may be contained within containers including porous woven fabric containers.
Surface active agents have also been used for the removal of oil from contaminated aqueous surfaces wherein the surface active agent emulsifies the discharged oil. The emulsion fosters the precipitation of oil as it sinks to the bottom of the aqueous body.
Other methods have been reported wherein a chemical agent is used to congeal oil to produce a stiffened mass or gel. The congealed oil is then placed onto a net or screen which holds the congealed oil while allowing water to drain through the net or screen.
Attaining an even distribution of treatment agents onto contaminated surfaces has proven to be difficult. This has been seen in the application of such absorbents in waterways as well as on ground surfaces. Further, while many of the absorbents previously reported have been successful in attracting spilled oil, the collection of the composite of absorbent and oil is often difficult as the composite has been unable to remain on the surface of the aqueous body.
A need exists for a treatment agent which, when oil is sorbed thereto, exhibits enhanced stability. In addition, a need exists for a sorbent which, when combined with the spilled oil, forms a composite which will not sink into the waterway. There is further a need for a sorbent which may be more evenly applied over the area defined by the oil spill than offered by the systems of the prior art.
It should be understood that the above-described discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related application or patent should be limited by the above discussion or construed to address, include or exclude each or any of the above-cited features or disadvantages merely because of the mention thereof herein.